We are ignorant of many things which would not be hidden from us if the reading of old authors was familiar to us.

Explanation

(English-origin maxim.) Many modern legal errors arise from neglect of the old authorities — counsel should study Coke, Blackstone, and the ancient reports, because the principles established there remain the foundation of the common law.

Where this applies

• A court corrects a widespread misunderstanding of a constitutional clause by returning to the original debates and founding-era treatises that modern lawyers had stopped reading.
• A legal researcher discovers that a commonly accepted interpretation of a statute contradicts what Blackstone wrote on the same subject centuries earlier, proving that neglecting old authorities leads to error.
• A judge notes in an opinion that had counsel consulted Coke's Institutes, the answer to the disputed point of common law would have been obvious — ignorance of the old authors bred unnecessary confusion.